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measurement mode, displays stable measuring value and calibration guide
icons. Please see Diagram–11 for the above calibration process.
6) During the calibration process, press key
to exit from
the calibration
mode. The meter can perform one-point, two-point and three-point calibration.
Calibration guide icons appear on LCD.
4.3 Customized Calibration
(take 1.60pH and 6.50pH calibration solution as an example)
1) Select
CUS
from parameter P1.1 (please refer to Item 8.3 for customer-defined solution). The meter
enters into Customer-defined calibration mode. When press
key, the meter’s display shows a
blinking
CAL1
icon at the top right of LCD, indicating the meter enters into the 1
st
point customer-defined
calibration.
2) Rinse pH electrode in pure water, allow it to dry, and submerge it in pH1.60 buffer solution. Stir the
solution briefly and allow it to stay in the buffer solution until a stable reading is reached. When LCD
displays the stable measuring value and icon, press key and the measuring value flashes.
Press key or key to adjust the measuring value to 1.60, then press key to calibrate the
meter. After calibration is done, LCD at the top right shows blinking CAL2 icon, indicating the meter enters
into the 2
nd
point customer-defined calibration.
3) Rinse pH electrode in pure water, allow it to dry, and submerge it in pH 6.50 buffer solution. Stir the
solution briefly and allow it to stay in the buffer solution until a stable reading is reached. When LCD
displays the stable measuring value and icon, press key and the measuring value flashes.
Press key or key to adjust the measurement value to 6.50, then press key to calibrate the
meter. After calibration is done, the meter returns to the measurement mode. For customer-defined
calibration, LCD does not show electrode calibration guide icons.
Note: For manual temperature compensation (MTC), when press key, the temperature value
flashes. Press key or key to adjust the temperature value, and then press key, pH
measuring value flashes.
4) Notes
(a) The meter can perform 1-2 point customer-defined calibration. When the 1
st
point calibration is done,
press key, the meter exits from calibration mode. This is one-point customer-defined calibration.
When the 2
nd
point calibration is done, the meter returns to the measurement mode automatically.
(b) The value set in “Customer-defined” is at a fixed temperature. The meter is suggested to perform
calibration and measurement at the same temperature to avoid large error. The meter cannot recognize
customer-defined calibration solution.
4.4 Sample test
1) Rinse pH electrode in distilled water, dry it, and dip it in sample solution. Stir the solution gently and let
